SBCL. Works everywhere, super fast, has an advanced compiler with helpful warning messages. You get a fully featured Common Lisp implementation with all the goo

SBCL. Works everywhere, super fast, has an advanced compiler with helpful warning messages. You get a fully featured Common Lisp implementation with all the goodies like CLOS, threads, C interoperability, and so on. And of course no Java required (though there is a Common Lisp implementation (ABCL) written in Java).